A hermetic compressor is disclosed in U.S. Pat. No. 5,496,156 for instance, in which an inlet opening of a suction muffler is disposed closely facing a suction pipe for achieving a high efficiency. The conventional hermetic compressor is explained hereinafter with reference to a drawing.
FIG. 4 is a cross-sectional view of the conventional hermetic compressor. Suction pipe 2 which opens into hermetic container 1 is fixed with hermetic container 1. Hermetic container 1 contains compressing mechanism 7 which includes cylinder 4 in which piston 3 reciprocates, and suction muffler 6 forming muffling space 5. Suction muffler 6 is provided with inlet opening 8 communicating muffling space 5 with a space of inside hermetic container 1. Inlet opening 8 is disposed closely facing suction pipe 2.
A motion of thus constituted hermetic compressor is explained next. Piston 3 reciprocates inside cylinder 4, thereby cooling medium flowing from an external refrigerating system (not illustrated) through suction pipe 2 is once released into hermetic container 1. The cooling medium is drawn into suction muffler 6 through inlet opening 8, and then intermittently drawn into cylinder 4 through muffling space 5. At this time, since suction pipe 2 and inlet opening 8 are closely faced each other, the cooling medium is drawn into suction muffler 6 with keeping its relatively low temperature. Consequently, drawn mass of the cooling medium (cooling medium circulating amount) per unit period of time becomes large therefore efficiency is increased, thus efficiency of the hermetic compressor is enhanced.
However, with above-mentioned constitution, when the cooling medium is released through suction pipe 2 into hermetic container 1, the cooling medium is mixed with high temperature cooling medium that already exists in the hermetic container 1. Thereby, the temperature of the cooling medium introduced by inlet opening 8 into cylinder 4 becomes higher than the cooling medium at an opening portion of suction pipe 2. Because of the reason, cooling medium circulating amount is reduced, insufficiently enhancing efficiency of the compressor.